I ran into this software (HydroFlow [1]) from Rio de Janeiro State University that will give you river order (srahler or Shreve) based only on a vector river network and a basin map. I tested it on a large basin and it did work fine but, you must have a topologically correct vector. Hope it helps
Daniel [1] http://www.fgel.uerj.br/labgis/hydroflow/en/index_ingles.htm On Tue, Jan 25, 2011 at 10:03 AM, Hamish <[email protected]> wrote: > Hi, > > I see v.strahler and r.stream.order in addons can assign > Strahler Order to a river network, but how to run that if you > are starting with an existing vector river network with no > raster DEM? could you cross with a matching coastline vector to > extract end nodes at the river mouths? will even a rough DEM > like SRTM data be better than nothing in that case? how good > does it have to be? would etopo1 be ok? (1 arc-minute ~ 2 km > cells) > > also, how to get around attaching lake and swamp areas which > split the river vector line in two? convert their boundaries to > lines and treat it as a braided river? fill them in then r.thin > them somehow? otherwise topology would be clean. > how about if the river goes into a cave and out somewhere else? need to trace > that gap by hand? (may be too big for the sloppy= > option) > > > thanks for any tips, > Hamish > > > > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
